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31.
Fetal trophoblasts can be found in maternal circulation from an early stage of pregnancy and thus provide a potential source of DNA for non-invasive prenatal diagnosis. We have developed a two-step method for trophoblast isolation between the 8th and 12th week of pregnancy. Blood was sampled from 14 women undergoing termination of pregnancy or spontaneous abortion. Immunomagnetic beads precoated with HLA class I and II, and with anti-cytokeratin-18 monoclonal antibodies, were used to remove CD8+ and other maternal cells, and to select for fetal trophoblasts, respectively. Microsatellite analysis was performed on DNA extracted from the isolated, maternal, paternal and placental cells after PCR amplification. Recovery of the trophoblasts was confirmed in 13/14 cases (93%) by the identification of an identical microsatellite pattern for fetal and placental cells. Further evidence was the presence of heterozygous alleles of both maternal and paternal origin. The correct prediction of gender in all five male fetuses was an additional confirmation of trophoblast recovery. We conclude that trophoblasts can be effectively isolated from maternal blood in the first trimester, and by using polymorphic microsatellite markers to confirm sample purity, this method has potential future application in prenatal diagnosis. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
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Environmental Science and Pollution Research - The development of agriculture is linked to energy resources. Consequently, energy analysis in agroecosystems could be a useful tool for monitoring...  相似文献   
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In the present study, the exposure to benzene of employees working in two filling stations (one urban and one rural) was estimated, through the method of passive sampling. Additional data (30′ measurements of benzene exposure through active sampling to employees dealing with different activities, meteorological and traffic data) were collected. The measurements campaign was performed in both summer and wintertime to determine the seasonal variation of the exposure pattern.In addition, a set of artificial neural networks (ANNs) was developed to predict benzene exposure pattern for the filling station employees based on active sampling data and the parameters related to the employees’ exposure. The quantification of the contribution of each parameter to the overall exposure pattern was also attempted.The results showed that although vapour recovery technologies are installed in the refuelling systems and benzene emissions are significantly reduced compared to the past, filling station employees are still highly exposed to benzene (52–15 μg m−3). Benzene exposure is strongly correlated to car refuelling (exposure levels up to 85 μg m−3), while activities like car washing or working in cash machine inside an office contribute to lower exposure levels (up to 44 and 24 μg m−3 respectively). In rural filling station, exposure levels were in general lower compared to the urban ones, due to the smaller amount of gasoline that was traded and the absence of any significant traffic effect or urban background concentration. The developed ANN seemed to be a promising technique in the prediction of the exposure pattern giving very good results, and the quantification of the parameters affirmed the importance of the refueling procedure to the exposure levels.  相似文献   
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The aim of this study is to evaluate whether a specific recycling system for used oil filters (UOFs) is environmentally viable by considering all steps of the product's life cycle. In that aspect an analysis of the environmental impacts regarding different waste management scenarios of UOFs in Greece is presented using the Life Cycle Assessment (LCA) approach. Waste scenarios varied from maximum feasible recycling and recovery of metals and used lubricant oil, to disposal of UOFs to landfills without any prior treatment. In order to perform this analysis, the principles of ISO 14040 were followed and a relevant LCA software was used (SimaPro 7.2). Additionally, the results of a previous work conducted by the authors were deployed, including some experimental measurements undertaken so as to evaluate and quantify the factors affecting the recovery of the lubricant oil contained in used automotive filters. Indicatively, it was estimated that a maximum of 1340 tons of used oil and 1810 tons of steel are disposed every year in Greece, as a result of the non-effective management of used automotive filters.  相似文献   
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Environment, Development and Sustainability - Dive tourism has been growing constantly in recent years, contributing to socio-economic development of coastal zones and islands. In Greece new users...  相似文献   
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Coastal zones attract a large number of people and productive activities. This puts pressure on ecosystems and affects the organization of local economies, having an impact on social cohesion and coherence. The complexity of coastal socio-spatial systems and the fact that coastal zones, and, more particularly, islands that are considered vulnerable areas (that is, parameters: such as sea level rising, desertification, built-up areas excessive expansion etc) and important for the overall operation of the state imply the significance of a further study of the subject. The paper deals with the principal socio-spatial pressures on coastal zones and islands that are caused by unregulated urban growth. The incompetent spatial planning framework, the “loose” political system, related to urban growth, and the socio-economical characteristics are considered as the principal reasons for built-up areas excessive dispersion. Here, delineation of the coastal zone is proposed, using physico-geographical and man-made variables. Soil Sealing dataset is used to illustrate where built-up areas dispersion and basic metrics can be applied. Furthermore, an overview of the planning spatial framework is attempted, so that the particularities of urban growth can be interpreted.  相似文献   
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In this work, the elemental content (C, N, H, S, O), the organic matter content and the calorific value of various organic components that are commonly found in the municipal solid waste stream were measured. The objective of this work was to develop an empirical equation to describe the calorific value of the organic fraction of municipal solid waste as a function of its elemental composition. The MSW components were grouped into paper wastes, food wastes, yard wastes and plastics. Sample sizes ranged from 0.2 to 0.5 kg. In addition to the above individual components, commingled municipal solid wastes were sampled from a bio-drying facility located in Crete (sample sizes ranged from 8 to 15 kg) and were analyzed for the same parameters. Based on the results of this work, an improved empirical model was developed that revealed that carbon, hydrogen and oxygen were the only statistically significant predictors of calorific value. Total organic carbon was statistically similar to total carbon for most materials in this work. The carbon to organic matter ratio of 26 municipal solid waste substrates and of 18 organic composts varied from 0.40 to 0.99. An approximate chemical empirical formula calculated for the organic fraction of commingled municipal solid wastes was C32NH55O16.  相似文献   
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